lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 12 Sep 2014 01:45:03 +0400
From: Solar Designer <solar@...nwall.com>
To: discussions@...sword-hashing.net
Subject: Re: [PHC] A review per day - Lyra2

On Thu, Sep 11, 2014 at 07:35:31PM +0100, Samuel Neves wrote:
> On the 32-bit version of the permutation, it is straightforward to replace vpaddd with vpmulld + vpaddd.

As discussed before, (V)PMULLD has 10 cycles latency on Haswell and 11
cycles on Silvermont/Avoton, as opposed to 5 cycles for other multiply
instructions on the same CPUs.  But I guess this may be acceptable, if
this specific approach has other advantages over possible alternatives.
On most other CPUs, (V)PMULLD is fast.

In yescrypt, I chose to avoid the need for this instruction, though,
opting to rely on 32x32->64 multiplies instead, which is (V)PMULUDQ
(but twice fewer of these fit per vector).

Alexander

Powered by blists - more mailing lists